Zone control valve for vacuum film holder



Dec. 8, 1970 1.. w. HUTCHINS ZONE CONTROL VALVE FOR VACUUM FILM HOLDER 2Sheets-Sheet 1 Filed July 15, 1968 \\\l I I mwwx r02 IIIMII 5 lNVENTORLOREN W- HUTCHINS BY q $71M,

ATTORNEYS De. 8, 1970 L. w. HUTCHINS 3,545,350

ZONE CONTROL VALVE FOR VACUUM FILM HOLDER Filed July 15, 1968 2Sheets-Sheet 3 (D INVENTOR I LOREN W. HUTCHINS 4%, JAM, @M

ATTORNEYS United States Patent 3,545,860 ZONE CONTROL VALVE FOR VACUUMFILM HOLDER Loren W. Hutchins, Detroit, Mich., assignor to DouthittCorporation, Detroit, Mich. Filed July 15, 1968, Ser. No. 744,891 Int.Cl. G03b 27/20 US. Cl. 355-91 4 Claims ABSTRACT OF THE DISCLOSURE Anopen face vacuum film holder having a'vacuum source and a vacuum boardwhich includes a pan and a series of partitions therein defining aplurality of concentric vacuum chambers, each having a vacuum inlet. Arigid porous sheet is sealed over said pan and partition to define aseries of independent vacuum zones. A slide valve is provided under andbearing against the pan, has an inlet connected to the vacuum source anda stepped zone control chamber. Manually controlled movement of thevalve selectively connects the vacuum source with one or a plurality ofsaid zones successively. Heretofore in vacuum holders of this nature, aphotosensitive unexposed film of a predetermined dimension is centrallyapplied to the open face vacuum board being correctly located for itsdimension. There is directly applied to the said film a positive or anegative print and wherein by the use of the vacuum bed both are pulledflat against each other and fiat against the bed during the exposureprocess using a high intensity lamp for a short predetermined period.

In holders of this type, the print may be of a small size as for example4 x 5 inches, 5 x 7 inches or 8 x 10 inches, or may be larger in therange of 14 X 17 inches, 20 x 24 inches or 32 x 32 inches.

It is an object of the present invention to provide an open face vacuumfilm holder which has within its vacuum board a series of concentricrectangular zones selectively connected to a vacuum source so that if asmall size print is employed, the entire vacuum communication isdirected to that zone and wherein valve means are provided by which forincreasingly larger prints additional concentric vacuum zones may beactivated so that the full vacuum strength is directed only to thosezones over which the print lies for the exposure process.

It is another object of the present invention to provide a novel slidevalve construction manually operable by which the total vacuum sourcedirects full vacuum to the areas or zones employed during the printingprocess, but wherein means are provided whereby zones exterior to theboundaries of the print during printing cut off from a vacuum sourcewhich would otherwise be open to the atmosphere.

It is a further object to provide a novel form of slide valve controlfor regulating the delivery of vacuum from the vacuum source of theprinter selectively to the zone or adjacent zones over which the printis centrally located to thus provide for the best utilization of thevacuum source, and wherein a very small powered pump may be utilizedregardless of the zones selected.

DETAILED DESCRIPTION An illustrative embodiment of the invention isdisclosed in the attached drawings in which FIG. 1 is a frontelevational view of the present open face vacuum film holder.

FIG. 2 is a plan view on an increased scale and partly broken away forillustration.

3,545,860 Patented Dec. 8, 1970 "ice- FIG. 3 is a section taken in thedirection of arrows 3-3 of FIG. 2.

FIG. 4 is a section taken in the direction of arrows 4-4 of FIG. 2; and,

FIG. 5 is a fragmentary section taken in the direction of arrows 5-5 ofFIG. 2.

Referring to the drawing, the present open face film holder 11 includeshousing 12 with legs 13 and incorporating a shelf 14 and front panel 15mounting the off and on switch 16 for interconnecting power source 17with vacuum pump 18 mounted upon shelf 14.

A vacuum board 19 overlies and is coextensive with the top of housing 12and includes upon its undersurface the adjustable zone control slidevalve 20 having a vacuum inlet fitting 21 and attached thereto theflexible hose 22 which connects the vacuum pump or other vacuum source.

The vacuum board includes a preferably metallic pan 23 which includes aperipheral upright side wall and a pan bottom, FIG. 3.

A series of continuous upright partitions 24, 25 and 26 mounted withinsaid pan are coextensive with its side wall and thus define with saidpan a plurality of concentric preferably rectangular vacuum chambers A,B, C and D, FIG. 2.

Applied to the side wall of the pan 23, as well as the top edge of thepartition 24, 25 and 26, is a continuous strip of sponge rubber 27 whichhas adhesive on its opposite sides in order to adhere to the pans sidewall and partitions and at the same time compressively and cooperativelyand sealingly engage the undersurface of the rigid porous sheet or strip28. In the illustrative embodiment of the present device, the sheet isconstructed of a sintered Steel and is porous throughout.

Applied to the top surface of the said porous sheet 28 and correctlycentered, are suitable indicia 29, FIG. 2, which correspondingly definethe respective corners and location points for film and prints dependingon their sizes and corresponding respectively to the outer boundaries ofthe respective chambers B, C and D to thus assist in correct location ofthe film and print over the vacuum board for an exposure process.

Within the bottom wall of pan 23 are a series of vacuum inlets 30arranged in a row, FIG. 2, which communicate respectively with each ofthe vacuum zones or chambers A, B, C and D.

By the present construction, the porous sheet which is coextensive withthe top surface of the pan thus defines with the pans side wall and thesaid chambers, a series of independent vacuum zones A, B, C and D.

The present slide valve or zone control valve generally indicated at 20includes a generally rectangular valve body 31 having a Teflon top sheet32 and a metallic bottom plate 33. The body includes upon its interiorstepped zone control chamber 34, which is adapted for cooperativeregistry selectively with one or more of the vacuum inlets 30 upon theundersurface of the pan 23.

The said slide control valve is slidably mounted upon the undersurfaceof the said pan with the Teflon top plate of the valve body sealinglyand slidably engaging with reduced friction the undersurface of said panbottom.

As viewed in FIG. 2, the zone control chamber has a series of steps bywhich it is seen in the position of the valve body shown in FIG. 2, thatthe control chamber is in communication only with the vacuum inlet 30registering with vacuum chamber D. It is seen furthermore that shouldthe valve body be moved from its present position rearwardly a shortdistance, an additional vacuum inlet to chamber C would be incommunication with the valve control chamber 34. Further, longitudinaladjustment of the valve body in the same direction exposes in additionto the first mentioned two inlets 30 the additional inlet 30 whichcommunicates with vacuum zone B. Furthermore, on further longitudinaladjustment in the same direction of the valve body the fourth vacuuminlet 39 in the pan would be in communication with the zone controlchamber to thus establish vacuum communication to all of the vacuumchambers A, B, C and D. This would be a situation where the largest sizenegative or print is employed which is substantially coextensive withthe outer boundaries of the vacuum bed 28.

The slide mounting of the vacuum control valve upon the undersurface ofpan 23 includes a pair of opposed spaced Z-shaped channels, guides 35,FIG. 4, upon which the slide valve is movably mounted for transverseadjustment as shown in FIG. 2.

For this purpose, the link 36 is pivotally connected at one end to thevalve body at 37 and at its opposite end is pivotally connected as at 40to the free end of the selector control arm 38.

The latter arm is pivotally mounted upon the undersurface of the pan asat 39 with its free end, FIG. 2, projecting through control plate 41which is suitably slotted and notched as at 42 to thereby determine theangular adjustments of the selector arm 38 from the position shown inFIG. 2 to the extreme dotted line position shown therein, and whereinvacuum communication would be established to all of the zones A, B, Cand D.

It is noted that the slot formed within the control plate 41 isof suchlength as to limit the angular movements of the selector arm 38 and alsoto predetermine the four locations thereof which correspond to therespective zones A, B, C and D to which it is desired that vacuum bedirected.

In use, if the negative and print involved is of a dimension of asmaller nature such as 4 x 5 inches, 5 x 7 or 8 x 10 inches, then thesame is located with respect to the indicia 29 so as to overlie only thevacuum zone D. In the position of the slide valve in FIG. 2, only thatzone is in full communication with the vacuum source.

Should the next size print be employed such as 14 x 17 inches, then itis necessary to adjust the selector arm 38 to register with the firstnotch 42. This would cause a corresponding sliding movement of the valve20 so as to expose the second vacuum inlet to the vacuum control chamber34.

The valve body 20 upon its undersurface has secured thereto the inletfitting 21 which is suitably connected to the vacuum source by flexibleconduit 22, FIG. 1.

For a larger print such as the size 20 x 24 inches, then it is necessarythat the selector arm 38 be moved further along the slot within theplate 41 to the second notch. At this location, the slide valve 20 wouldbe so moved that vacuum communication is now established to all three ofthe chambers D, C and B, etc.

Having described my invention, reference should now be had to thefollowing claims.

I claim:

1. In an open face vacuum film holder;

a housing mounting a vacuum source;

a horizontally disposed vacuum board on said housing including a panhaving a bottom and a peripheral wall;

a series of continuous upright partitions within said pan coextensivewith said wall and defining with said pan a plurality of concentricrectangular vacuum chambers;

there being a series of spaced inlets in said pan bottom andcommunicating with said chambers respectively;

a rigid porous sheet coextensive with and overlying said pan in sealingregistry with the pan wall and said partitions separating said chambersinto a series of independent vacuum zones;

a slide valve on the exterior of and bearing against the pan bottom andguidably mounted thereunder for reciprocal movements in a direction atright angles to said row of inlets;

said valve including an apertured body having a top wall and a bottomwall with a vacuum fitting, said body having a portion with a series oflongitudinal steps defining in said body a stepped zone control chamber,adapted on adjustment for establishing communication of vacuum from saidchamber progressively with said inlets;

a conduit interconnecting said fitting and said vacuum source;

and a selector arm intermediate its ends pivotally mounted upon saidpan, at one end pivotally connected to said valve and at its other endprojecting laterally of said pan for manual movements for establishingfull vacuum communication to one vacuum zone and successively toadditional vacuum zones as required depending upon the size of thenegative to be printed.

2. In the film holder of claim 1, said body including a metal bottomwall mounting said vacuum inlet fitting, and a Teflon top wall sealinglyengaging said pan.

3. In the film holder of claim 1, the connection of said selector armand valve including a link;

and an apertured arm support at one edge of and depending from said panguidably receiving said selector arm, and including a plurality ofspaced arm control notches.

4. In the film holder of claim 1, a series of concentric printing sheetlocating indicia of rectanugular shape applied to said porous sheet,corresponding to and in registry with each of said vacuum zonesrespectively.

References Cited UNITED STATES PATENTS 2,799,205 7/1957 Bacsik 355762,895,706 7/1959 Blatherwick 35573X 2,905,428 9/1959 Ribesehl et al.35573X 3,222,051 12/1965 Bevilacqua et al. 35576X 3,229,953 l/l966 Muir35573X JOHN M. HORAN, Primary Examiner R. L. MOSES, Assistant ExaminerUS. (:1. X.R. $-73, 7

